Path: utzoo!attcan!uunet!lll-winken!ames!amelia!wk46!yamo
From: yamo@wk46..nas.nasa.gov (Michael Yamasaki)
Newsgroups: comp.sys.super
Subject: Re: I/O subsystems (was Re: Supercomputer ROI)
Message-ID: <6392@amelia.nas.nasa.gov>
Date: 30 May 90 16:40:21 GMT
References: <201@csinc.UUCP> <253@garth.UUCP> <202@csinc.UUCP> <292@garth.UUCP> <10280@batcomputer.tn.cornell.edu> <359@garth.UUCP> <6374@amelia.nas.nasa.gov> <56754@bbn.BBN.COM>
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Reply-To: yamo@wk46.nas.nasa.gov (Michael Yamasaki)
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In article <56754@bbn.BBN.COM> lkaplan@BBN.COM (Larry Kaplan) writes:
>
>There are some true "killer micros" that address I/O issues on the market
>right now.  BBN's newer "Butterfly" machine (TC2000) can be configured with
>one I/O bus (read VME) for about every TWO processors.
> [...]
>These busses communicate with memory at a peak of 8 Mbytes/sec.  
> [...]
>One existing customer has 9 disks on five I/O busses.
>

Combined peaks of these five I/O busses is somewhat less than a single
HPPI interface, less than half of an HSX (at 100 MBytes/sec.). Again,
the numbers I used for the Cray 2 were for a typical single processor job
with 50 or so other users on the system.

>This amount of I/O is starting to look reasonable for a killer micro.
>Some work remains to be done, however, in getting the software to effectively
>use all of the bandwidth.
>

(an exersize for the reader? ;-)  Really, this doesn't seem like a trivial
problem to me.


                                       -Yamo-
                                 yamo@wk46.nas.nasa.gov
                                yamo@amelia.nas.nasa.gov
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